usr/src/uts/common/sys/flock.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  23 /*        All Rights Reserved   */
  24
  25
  26 /*
  27  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 /*
  31  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  32  */
  33
  34 #ifndef _SYS_FLOCK_H
  35 #define _SYS_FLOCK_H
  36
  37 #include <sys/types.h>
  38 #include <sys/fcntl.h>
  39 #include <sys/vnode.h>
  40 #include <sys/t_lock.h>         /* for <sys/callb.h> */
  41 #include <sys/callb.h>
  42 #include <sys/param.h>
  43 #include <sys/zone.h>
  44
  45 #ifdef  __cplusplus
  46 extern "C" {
  47 #endif
  48
  49 /*
  50  * Private declarations and instrumentation for local locking.
  51  */
  52
  53 /*
  54  * The flag passed to fs_frlock() may be ORed together with either
  55  * `F_REMOTELOCK' or `F_PXFSLOCK'.  Since this flag is initialized using the
  56  * `f_flag' field in the `file' structure, and that field is an unsigned short,
  57  * we do not use the first 2 bytes.
  58  */
  59 #define F_REMOTELOCK    (0x01 << 16) /* Set if NLM lock */
  60 #define F_PXFSLOCK      (0x02 << 16) /* Clustering: set if PXFS lock */
  61
  62 /*
  63  * The command passed to reclock() is made by ORing together one or more of
  64  * the following values.
  65  */
  66
  67 #define INOFLCK         0x01    /* Vnode is locked when reclock() is called. */
  68 #define SETFLCK         0x02    /* Set a file lock. */
  69 #define SLPFLCK         0x04    /* Wait if blocked. */
  70 #define RCMDLCK         0x08    /* F_REMOTELOCK specified */
  71 #define PCMDLCK         0x10    /* Clustering: F_PXFSLOCK specified */
  72 #define NBMLCK          0x20    /* non-blocking mandatory locking */
  73
  74 /*
  75  * Special pid value that can be passed to cleanlocks().  It means that
  76  * cleanlocks() should flush all locks for the given sysid, not just the
  77  * locks owned by a specific process.
  78  */
  79
  80 #define IGN_PID         (-1)
  81
  82 /* file locking structure (connected to vnode) */
  83
  84 #define l_end           l_len
  85
  86 /*
  87  * The lock manager is allowed to use unsigned offsets and lengths, though
  88  * regular Unix processes are still required to use signed offsets and
  89  * lengths.
  90  */
  91 typedef ulong_t u_off_t;
  92
  93 #define MAX_U_OFF_T     ((u_off_t)~0)
  94 #define MAX_U_OFFSET_T  ((u_offset_t)~0)
  95
  96 /*
  97  * define MAXEND as the largest positive value the signed offset_t will hold.
  98  */
  99 #define MAXEND          MAXOFFSET_T
 100
 101 /*
 102  * Definitions for accessing the l_pad area of struct flock.  The
 103  * descriminant of the pad_info_t union is the fcntl command used in
 104  * conjunction with the flock struct.
 105  */
 106
 107 typedef union {
 108         int     pi_pad[4];              /* (original pad area) */
 109         int     pi_has_rmt;             /* F_HASREMOTELOCKS */
 110 } pad_info_t;
 111
 112 #define l_has_rmt(flockp)       (((pad_info_t *)((flockp)->l_pad))->pi_has_rmt)
 113
 114 /*
 115  * Optional callbacks for blocking lock requests.  Each function is called
 116  * twice.
 117  * The first call is after the request is put in the "sleeping" list, but
 118  *   before waiting.  At most one callback may return a callb_cpr_t object;
 119  *   the others must return NULL.  If a callb_cpr_t is returned, the thread
 120  *   will be marked as safe to suspend while waiting for the lock.
 121  * The second call is after the request wakes up.  Note that the request
 122  *   might not have been granted at the second call (e.g., the request was
 123  *   signalled).
 124  * New callbacks should be added to the head of the list.  For the first
 125  * call the list is walked in order.  For the second call the list is
 126  * walked backwards (in case the callbacks need to reacquire locks).
 127  */
 128
 129 typedef enum {FLK_BEFORE_SLEEP, FLK_AFTER_SLEEP} flk_cb_when_t;
 130
 131 struct flk_callback {
 132         struct flk_callback *cb_next;   /* circular linked list */
 133         struct flk_callback *cb_prev;
 134         callb_cpr_t     *(*cb_callback)(flk_cb_when_t, void *); /* fcn ptr */
 135         void            *cb_data;       /* ptr to callback data */
 136 };
 137
 138 typedef struct flk_callback flk_callback_t;
 139
 140 /*
 141  * This structure members are not used any more inside the kernel.
 142  * The structure is used for casting some pointer assignments only.
 143  */
 144
 145 typedef struct filock {
 146         kcondvar_t cv;
 147         struct  flock set;      /* contains type, start, and end */
 148         struct  {
 149                 int granted_flag;       /* granted flag */
 150                 struct filock *blk;     /* for sleeping locks only */
 151                 struct attacher *blocking_list;
 152                 struct attacher *my_attacher;
 153         }       stat;
 154         struct  filock *prev;
 155         struct  filock *next;
 156 } filock_t;
 157
 158 #define FLP_DELAYED_FREE        -1      /* special value for granted_flag */
 159
 160 /* structure that contains list of locks to be granted */
 161
 162 #define MAX_GRANT_LOCKS         52
 163
 164 typedef struct grant_lock {
 165         struct filock *grant_lock_list[MAX_GRANT_LOCKS];
 166         struct grant_lock *next;
 167 } grant_lock_t;
 168
 169 /*
 170  * Provide a way to cleanly enable and disable Network Lock Manager locking
 171  * requests (i.e., requests from remote clients):
 172  *    FLK_NLM_SHUTTING_DOWN: Forces all blocked NLM requests to bail out
 173  *      and return ENOLCK.
 174  *    FLK_NLM_DOWN: Clears all granted NLM server locks.  Both status
 175  *      codes cause new NLM lock requests to fail immediately with ENOLCK.
 176  *    FLK_NLM_UP: Changes the state of all locks to UP, after a server has
 177  *      shutdown and is restarting on the same node.
 178  */
 179
 180 /*
 181  * Enumerated type of the four possible states an NLM server can be in.
 182  */
 183 typedef enum {
 184         FLK_NLM_UP,
 185         FLK_NLM_SHUTTING_DOWN,
 186         FLK_NLM_DOWN,
 187         FLK_NLM_UNKNOWN
 188 } flk_nlm_status_t;
 189
 190 /*
 191  * Provide a way to cleanly enable and disable lock manager locking
 192  * requests (i.e., requests from remote clients).  FLK_WAKEUP_SLEEPERS
 193  * forces all blocked lock manager requests to bail out and return ENOLCK.
 194  * FLK_LOCKMGR_DOWN clears all granted lock manager locks.  Both status
 195  * codes cause new lock manager requests to fail immediately with ENOLCK.
 196  */
 197
 198 typedef enum {
 199     FLK_LOCKMGR_UP,
 200     FLK_WAKEUP_SLEEPERS,
 201     FLK_LOCKMGR_DOWN
 202 } flk_lockmgr_status_t;
 203
 204 #if defined(_KERNEL) || defined(_FAKE_KERNEL)
 205
 206 /*
 207  * The following structure is used to hold a list of locks returned
 208  * by the F_ACTIVELIST or F_SLEEPINGLIST commands to fs_frlock.
 209  *
 210  * N.B. The lists returned by these commands are dynamically
 211  * allocated and must be freed by the caller.  The vnodes returned
 212  * in the lists are held and must be released when the caller is done.
 213  */
 214
 215 typedef struct locklist {
 216         struct vnode *ll_vp;
 217         struct flock64 ll_flock;
 218         struct locklist *ll_next;
 219 } locklist_t;
 220
 221 #define FLK_QUERY_ACTIVE        0x1
 222 #define FLK_QUERY_SLEEPING      0x2
 223
 224 int     reclock(struct vnode *, struct flock64 *, int, int, u_offset_t,
 225                 flk_callback_t *);
 226 int     chklock(struct vnode *, int, u_offset_t, ssize_t, int,
 227                 caller_context_t *);
 228 int     convoff(struct vnode *, struct flock64 *, int, offset_t);
 229 void    cleanlocks(struct vnode *, pid_t, int);
 230 locklist_t *flk_get_sleeping_locks(int sysid, pid_t pid);
 231 locklist_t *flk_get_active_locks(int sysid, pid_t pid);
 232 locklist_t *flk_active_locks_for_vp(const struct vnode *vp);
 233 locklist_t *flk_active_nbmand_locks_for_vp(const struct vnode *vp);
 234 locklist_t *flk_active_nbmand_locks(pid_t pid);
 235 void    flk_free_locklist(locklist_t *);
 236 int     flk_convert_lock_data(struct vnode *, struct flock64 *,
 237                 u_offset_t *, u_offset_t *, offset_t);
 238 int     flk_check_lock_data(u_offset_t, u_offset_t, offset_t);
 239 int     flk_has_remote_locks(struct vnode *vp);
 240 void    flk_set_lockmgr_status(flk_lockmgr_status_t status);
 241 int     flk_sysid_has_locks(int sysid, int chklck);
 242 int     flk_has_remote_locks_for_sysid(vnode_t *vp, int);
 243 void    flk_init_callback(flk_callback_t *,
 244                 callb_cpr_t *(*)(flk_cb_when_t, void *), void *);
 245 void    flk_add_callback(flk_callback_t *,
 246                 callb_cpr_t *(*)(flk_cb_when_t, void *), void *,
 247                 flk_callback_t *);
 248 callb_cpr_t *flk_invoke_callbacks(flk_callback_t *, flk_cb_when_t);
 249
 250 /* Zones hooks */
 251 extern  zone_key_t flock_zone_key;
 252
 253 void    *flk_zone_init(zoneid_t);
 254 void    flk_zone_fini(zoneid_t, void *);
 255
 256 /* Clustering hooks */
 257 void    cl_flk_set_nlm_status(int nlmid, flk_nlm_status_t nlm_state);
 258 void    cl_flk_remove_locks_by_sysid(int sysid);
 259 int     cl_flk_has_remote_locks_for_nlmid(struct vnode *vp, int nlmid);
 260 void    cl_flk_change_nlm_state_to_unknown(int nlmid);
 261 void    cl_flk_delete_pxfs_locks(struct vfs *vfsp, int pxfsid);
 262 #endif /* _KERNEL */
 263
 264 #ifdef  __cplusplus
 265 }
 266 #endif
 267
 268 #endif  /* _SYS_FLOCK_H */